The present invention relates to a trowel handle and more particularly to a finishing trowel handle with a mounting and an interchangeable handle mounted thereto. The handle is angled and rounded at the front portion where the handle meets a post so as to provide a smooth, virtually flush transition between the post and the handle where the users thumb may be frequently placed.
A firm grip upon the handle of a trowel is advantageous to prevent the trowel from turning when troweling concrete or when its edge is being used for dozing concrete from one work area to another. When plastics such as glass-filled nylons, polyolefins, or wood are used for the handle, the low coefficient of friction of the smooth outer surface of the handle allows slippage of the trowel in the user's hand, particularly where the hand becomes wetted from perspiration or concrete.
The present invention's handle can be injection molded from two separate types of plastic, where an outer hand grip is molded from a thermoplastic rubber having a slightly soft, non-slip, rubber-like feel surface. This surface provides a favorable grippability to the handle, added ergonomic comfort for the user, and added aesthetic appeal to the handle's appearance. Furthermore, the inner part of the handle, as molded from a harder plastic, provides inner strength for mounting the handle and using the tool.
When trowels are used to spread concrete, the user tends to fully grasp the body of the handle for control of the angle of the trowel blade's working face presented to the work surface. The user's fingers and palm are prone to become chapped and may develop callouses wherever slippage or chafing occurs between the handle and the hand. A major factor promoting callousing of the hand is the presence of concrete. Concrete serves as an irritant by its abrasiveness as well as its chemical effect on the skin.
The present invention's inner core can be formed from polypropylene which provides a strong, durable, and resilient mounting surface. The polypropylene also provides a smooth, low friction area of transition from the body of the handle to the post where the thumb may rest. The friction of the polypropylene, relative to the friction of the outer hand grip and the post, can be controlled by varying the finish on the exposed portions of the inner core.
Alternatively, the entire handle can also be made from wood in the same exterior shape or other grippable, yet smooth materials which can be formed to have smooth and blended transition to the post.
Present finishing trowels often use injection moldable plastics, such as glass-filled nylons or polyolefins for the handle. However, when hollow plastic handles are used, watertight seals must be maintained around the joints in the component plastic parts because the complete tool is often submerged in water for cleaning. If water leaks into the handle's hollow cavities, then the weight advantage of a hollow structure may be reduced significantly. Often the manufacturing processes become complex and expensive to achieve the tolerances necessary for proper handle assembly with watertight seals.
The present invention provides a practical, ergonomic and effective solution which utilizes lightweight hollow handle cores and inexpensive sealing techniques for the components.
Additionally, injection molded handles are often non-replaceable as they are integrally molded onto the mounting. Heretofore, to be interchangeably replaceable, handles and their component parts and mountings, had to be made within exacting tolerances to achieve proper fit upon replacement. Also, replacement handles are often limited to one material which makes no provision for varied user preferences.
The present invention discloses replaceable parts which may be economically manufactured and interchanged without exacting tolerances to achieve a proper fit upon replacement. Additionally, alternative replacement materials may be used.